#include<stdio.h>
#include<assert.h>
char* my_strcpy(char* arr1, char* arr2)
{
	assert(arr1!= NULL);
	assert(arr2 != NULL);
	char* rest = arr1;
	while (*arr1++ = *arr2++)
	{
		;
	}
	return rest;
}
int main()
{
	char arr1[20];
	char arr2[20];
	gets(arr1);
	gets(arr2);
	my_strcpy(arr1, arr2);
	printf("%s\n", arr1);
	printf("%s\n", arr2);
	return 0;
}